1. Field of the Invention
This invention relates to a method of constructing single story building structures, particularly those utilizing lightweight steel, aluminum or wood members. The method invention is characterized by improvements in worker accessibility to the components being assembled and safety while achieving economy, efficiency and speed of construction in comparison with conventional construction procedures.
2. Description of the Prior Art
In the usual construction of single story lightweight steel buildings, it has become conventional to follow the procedure of grading the site to its approximate final elevation after which column footings of concrete are installed. Upright columns are then installed on these foundation footings, the column baseplate being anchored to the anchor bolts previously installed and projecting from these foundation footings.
Thereafter, beams are installed between the upper ends of the columns to be supported by the columns. Steel joists are placed on and welded to the beams with the usual joist spacing being in the order of five feet. Joist bridging is then installed at right angles to the joists to stabilize the entire assembly.
Finally, steel roof decking usually of formed sheet metal is placed transversely of the joists and welded to the joists. These roof deck sheets are usually 30 to 36 inches in width and formed to interlock so as to provide a continuous surface with each deck sheet being 20 feet, more or less, in length.
Single story buildings of the above described type are usually erected by installing, in order, columns, beams, joists and joist bridging. Under conventional construction procedures, each of these elements is individually lifted by crane and then secured in the place at the elevated level for the final roof structure of the building.
Generally, the roof deck sheets, in bundles, are then crane lifted to this elevated roof level and distributed out over the joists and thereafter welded to the joists to form the roof deck system. Insulation and roofing are then generally installed to complete this phase of the single story building structure.
A floor slab can be placed prior to or after erection of the above-mentioned structural frame. Then exterior walls and interior partitions are installed. Installation of electrical and mechanical facilities for the building follow to complete the building.
A drawback to the above-described prior art construction procedures for single story buildings is that a crane is required throughout the construction of the building and particularly its roof structure. This continous necessity for the presence of a lifting crane materially adds to the building cost.
Also the construction workers must carry out their work at the elevated height of the roof level in installing the beams, joists, joist bridging and roof decking. Aside from the hazards to these workers carrying out their duties at the elevated roof level, attempting to carry out these duties under marginal weather conditions can make working at these elevated heights unacceptably unsafe. Additionally, elevated platforms are needed for installing the electrical and mechanical facilities which are to be supported on or contained within the roof structure once it has been assembled at the top of the upstanding columns.
Attempts to overcome some of the above-mentioned disadvantages for the above-described conventional construction techniques for constructing a single story buildings have gone so far as to assemble a roof structure panel made up solely of joists and bridging at a location nearby the building site at ground level and thereafter raise this skeleton panel of joists and bridging for welding the ends of the joists to the beams which have already been secured between the upper ends of adjacent upstanding columns that are to support the roof structure. Still, this leaves a major portion of the construction work to be carried out at the elevated height of the roof level. All of the joists must be welded to the beams at the elevated roof level, the roof decking must be lifted, spread out and welded to the joists at the roof level and all of the electrical and mechanical facilities that are to be carried on or within the roof structure must be raised, installed and connected, also at the roof level height.